1. Field of the Invention
The invention relates to garlands of edible collagen casings for producing sausages and other foodstuffs.
2. Background Information
To produce sausages, natural intestines and increasingly synthetic intestines based on collagen or cellulose are used. For certain types of sausages, such as Bratwurst and Wxc3xcrstchen, almost without exception natural intestines, specifically sheepgut, have been used, since collagen-based casings have until now have been until now unable to meet traditional consumer expectations.
The production of thin-walled straight collagen casings is quite familiar to one skilled in the art, for instance from U.S. Pat. Nos. 3,535,125, 3,620,775, or 3,505,084, or from German Patent 972 854. It is also already known, as an alternative to the thick-walled, tough garlands of pork intestine, to use collagen casings as described for instance in German Patent 2 314 767. In these methods for producing garlands of sausage casings, rotating, conically continuous revolving surfaces are used; the extruded, inflated collagen casing is transported over a plurality of conically recessed supporting elements disposed one after the other, with the aid of adjustable hoisting devices, and at the same time dried with air heated to 50xc2x0 C. The garlands of collagen casings that can be made in this way cannot compare, however, with sheepgut in terms of their appearance or taste. By the method described in German Patent 2 314 767, it is also not possible to make thin-walled garland cases with a caliber range from 13 to 23 mm on an industrial scale, because that would require using low-viscosity collagen composition with a dry collagen content of 3.5 to 6.0%. Such a collagen compound is not sufficiently structurally firm, however, but instead is sticky, so that the production technique described in German Patent 2 314 767 is not suitable for producing such goods.
It is therefore the object of the invention to develop garlands of edible collagen casing that can be used as an alternative to the sheepgut.
To attain this object, edible collagen casings, having a caliber between approximately 13 and 23 mm and a wall thickness of less than 0.035 mm are proposed, which are characterized in that they are produced by means of a simultaneous treatment with ammonia and a coagulant that takes place directly after the extrusion, and by an ensuing garlanding process, known per se.
Surprisingly, it has now been found that tender thin-walled garlands of edible collagen casings can be produced on an industrial scale if the teaching of German Patent 2 314 767 is varied in such a way that the foil tube produced from the collagen suspension is treated on both the inside and the outside with coagulants directly downstream of the extrusion head; ammonia is used in the interior of the tube, while for the outer surface ammonia is again used, but preferably concentrated aqueous solutions of highly coagulant inorganic salts are employed. In this way, spontaneous coagulation of the vulnerable collagen extrudate is necessarily brought about. As a result of this provision, both the stickiness and the structural weakness of the freshly extruded, inflated collagen tube is already minimized, before it is placed on the conical transport segment of German Patent 2 314 767, far enough that continuous production of thin-walled small-caliber garlands of collagen casings with a caliber between 13 and 23 mm and a wall thickness of less than 0.035 mm is possible.
The delivery of the gaseous ammonia into the collagen tube is preferably accomplished through a feed line integrated with the extrusion head. Spraying the outer surface of the tube with a saturated solution of a strong coagulant is preferably done through spray nozzles arranged uniformly on the circumferential periphery of the tube. Following the coagulation, the collagen tube is predried and then washed to remove the inorganic salts that have formed; after that, the subsequent steps of tanning, softening, drying, remoistening, and coiling up or gathering up are completed as described in German Patent 2 314 767. These method steps are known and are state of the art, and are not the subject of this present invention.
The quantity of gaseous ammonia delivered to the interior of the tube, and both the quantity and concentration of the coagulant sprayed onto the outside of the surface can be varied within wide limits, as long as rapid coagulation of the freshly extruded tube of collagen compounds that are low in solids is reliably assured, which can be ascertained by simply preliminary tests.
The coagulation also reliably prevents sticking to the conical carrying and transport segments of the apparatus of German Patent 2 314 767, and moreover the simultaneous dual coagulation from the inside and the outside assures that tearing open of the tube when the extrudate is inflated with calibrating air will be lastingly prevented.
In principle, the dual coagulation from both the inside and the outside can be done with ammonia, but it is preferred that liquid coagulants be used for the outer surface, since they have a much more effective separating and lubricating action between the outer surface of the tube and the conical revolving faces. If only ammonia in gaseous form is used for both the inside and the outside, then the separating and lubricating effect is much less and is just barely acceptable, so that recurrent interruptions in production must be expected.
The collagen casings according to the invention preferably have an inside diameter of the garland ring of approximately 100 to 350 mm, because then they have an appearance equivalent to that of sheepgut. The wall thicknesses of the casing may either be equal, or it is also possible to use different wall thicknesses; preferably, the wall thickness of the inside diameter of the garland ring is slightly greater than that of the outside diameter of the garland ring.